books.google.com - Sexual drives are rooted in biology, but we don't act on them blindly. Indeed, as the eminently readable judge and legal scholar Richard Posner shows, we make quite rational choices about sex, based on the costs and benefits perceived. Drawing on the fields of biology, law, history, religion, and economics,...https://books.google.com/books/about/Sex_and_Reason.html?id=AgLmubyQqKoC&q=spouses&utm_source=gb-gplus-shareSex and Reason